UPDATE: Pascal from Twitter Wall Pro points out with a comment on this blog that the software offers both automatic or live moderation. Let me add that I sure think there is no problem with the software, but with the people using it in the wrong way.

Lesson learned: Never put together Silvio Berlusconi and Tweet Wall Pro in the same room during a public event.

Twitter is undeniably a great way to catch the vibe on what’s going on pretty much anywhere in the world, and trending topics and search / hashtags facilitate this tremendously. Kudos to the EU for experimenting with live Twitter stream projections at official summits in that regard … but they still need to learn that moderation is important, too.

Using Tweetwall Pro, a way for event organizers to feed live tweets onto screens, an experiment in the atrium of the EU summit building in Brussels held yesterday didn’t quite proceed as planned. The live tweet stream, which was displayed on multiple plasma TVs throughout the building, was abruptly shut down after Italian Twitter users hijacked the #euco stream with anti-Berlusconi messages, calling the politician a mafioso and a pedophile.

Read more from Robin Wauters on TechCrunch